Millennials have embraced the Supreme Court Justice with the hip-hop moniker Notorious RBG, liberals view her as their champion, and conservatives heap scorn — now with a new documentary about her life and legacy, she's ready to take Sundance by storm.

At 84, Supreme Court Justice Ruth Bader Ginsburg — who is expected to attend the world premiere of RBG, the documentary about her life and legacy that first screens at Sundance on Jan. 21 — could be the toast of the fest. "Millennials are big fans of hers," says Julie Cohen, who directed the film along with Betsy West. "What they love about her is the contrast between her seriousness of purpose and her lighter side."

Having embraced the hip-hop moniker Notorious RBG (originally bestowed upon her by an NYU law student), Ginsburg doesn't shy away from the notoriety or pop culture currency her nearly 25 years on the court have brought (though in October 2016 she said she'd never seen Kate McKinnon's portrayal of her on Saturday Night Live). She allowed the filmmakers, who worked on the project for three years, into her chambers and into her life outside the court.

They tag along as she mingles with her fans; visits the Santa Fe Opera (opera being a passion she shared with her ideological opposite but close friend, the late Antonin Scalia); and even as she goes through her daily workout routine. Adds West, "She's very proud, as an 84-year-old woman, that she keeps herself in shape."

CNN Films signed on as producer in the project's early stages. Explains Amy Entelis, who as CNN Worldwide's exec vp talent and content development oversees the cable net's documentary film unit, "Our audience is familiar with the court and its decisions, but putting her entire life's work in context — we don't get to do that on a daily basis."

In fact, the film argues, Ginsburg, who co-founded the Women's Rights Project at the American Civil Liberties Union in 1973, was instrumental in educating the court about gender inequality even before she became a Supreme. Including 1973's Frontiero v. Richardson, the first case she argued before SCOTUS — she successfully made the case that female service members deserve housing allowances just like their male counterparts — she won five of the six cases she brought to the Supreme Court.

"That's a theme of the film," says West. "When the justice began her career as a litigator, there were thousands of laws that discriminated against women — they couldn't get a credit card without their husband's permission, husbands in 12 states couldn't be prosecuted for raping their wives, and it went on and on. She took it on very strategically and systemically, a step-by-step strategy to convince justices, many of them male, that discrimination did exist. She says in the film, 'I felt like I was a kindergarten teacher.' "

As the doc tells it, when Ginsburg was installed on the court — she was nominated by President Clinton and approved by the Senate on a 96-3 vote — she initially staked out a relatively moderate, consensus-building position, but as subsequent appointments have driven the court to the right, she has become the great dissenter, unafraid to take her fellow justices to task.

Although she appears diminutive, her voice carries great weight and is heard throughout the film. While cameras have never been allowed into the court, there are audio recordings, which the RBG filmmakers make use of to capture those arguments. "We made the decision we were not going to shy away from those recordings even though there was no obvious picture to cover them," says Cohen. "The force of her voice, even in her very first Supreme Court argument, is so impressive. It's fun to hear her going from being a little tentative and nervous to being super-forceful."

RBG is one of two films CNN Films is bringing to Sundance this year, the other being Tim Wardle's Three Identical Strangers — the stranger-than-fiction account of three identical triplets, each raised separately, who only discovered each other at age 19 — which debuted in the U.S. Documentary Competition on Jan. 19. While Strangers may not have an immediate connection to current events like RBG, Entelis says, "It's such a compelling human interest story, I think our audience will connect to it. There's a universality to this story."

RGB and Three Identical Strangers also mark the 13th and 14th Sundance premieres that CNN Films has either produced or acquired. And Entelis herself — accompanied by Alexandra Hannibal, CNN Films associate director, and Courtney Sexton, CNN Films vp — is making her fifth visit as a buyer to Sundance, where CNN Films first began developing a name for itself by snapping up 2013's Blackfish, the influential doc that exposed SeaWorld's treatment of its killer whales.

Since then, CNN Films, as it's established its brand, has become a prime platform for airing new docs, having presented nearly 40, and has been joined by an associated label, CNN Films Presents, that offers encore broadcasts of existing docs like March of the Penguins.

As the market for new docs has heated up, thanks to players like Netflix, HBO and National Geographic, CNN Films has begun commissioning more of its own productions rather than depend entirely on acquisitions. But in making her pitch to filmmakers, whether they are pitching a project or shopping completed films, Entelis makes the same argument that "our approach to launching a film is definitely unique." Before airing new films, usually on a prime Sunday night time slot, CNN courts audiences by introducing each movie with segments and interview spots on the network's news shows and website. "It's a 360-degree approach," she says. "Filmmakers respond very positively to the promotion. You feel your film resonates and has meaning."

***

FOUR LIVES THAT HAVE DEFINED THEIR TIMESThe doc lineup looks at personalities as different as the gentle Fred Rogers and the confrontational Gloria Allred

Jane Fonda in Five Acts (HBO Documentary Films)

DIRECTOR Susan LacyBUZZ At 80, Jane Fonda has become a feminist icon — although earlier in her career she was often defined by the men in her life, a reality that Lacy's film doesn't gloss over as it traces the actress, activist and Academy Award winner's self-transformation.

Seeing Allred (Netflix)

DIRECTORS Sophie Sartain, Roberta GrossmanBUZZ High-profile ambulance chaser or idealistic women's rights champion? The filmmakers retrace Gloria Allred's 40-year-career as an attorney who often seems to spend as much time before the cameras as she does in court, taking on men from Bill Cosby to Donald Trump.

Won't You Be My Neighbor? (Focus Features)

DIRECTOR Morgan NevilleBUZZ The Oscar-winning director of 2013's 20 Feet From Stardom turns his attention to the late Fred Rogers, the Presbyterian minister turned children's entertainer and longtime PBS mainstay, in this doc that is already scheduled for a June 8 theatrical release.

Robin Williams: Come Inside My Mind (Jigsaw Productions)

DIRECTOR Marina ZenovichBUZZ Working with Alex Gibney's production company, the director, whose résumé includes two Roman Polanski documentaries, this time re-examines the life of the lightning-quick comedian, drawing on new interviews with those who knew him and fresh archival material like outtakes from Mork & Mindy.

A version of this story first appeared in the Jan. 17 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.